What is the dose of hypertonic saline (sodium chloride) solution?

From the Guidelines

Hypertonic saline should be administered as a 3% solution at an initial dose of 5 ml/kg i.v. over 15 minutes, with a maintenance dose of 1 ml/kg per hour i.v. to reach a target serum sodium level of 150–155 meq/l. This recommendation is based on the management guidelines for paediatric patients receiving chimeric antigen receptor T cell therapy, as outlined in the study published in Nature Reviews Clinical Oncology in 2019 1. The goal of hypertonic saline therapy is to reduce cerebral edema and manage intracranial hypertension.

Key Considerations

• The initial dose of 5 ml/kg i.v. over 15 minutes is crucial in rapidly reducing intracranial pressure and improving cerebral edema.
• The maintenance dose of 1 ml/kg per hour i.v. should be adjusted to reach a target serum sodium level of 150–155 meq/l, with frequent monitoring of electrolytes every 4 hours.
• It is essential to hold the infusion if the sodium level exceeds 155 meq/l to avoid complications.
• The use of hypertonic saline should be part of a comprehensive management plan that includes elevating the head of the bed, hyperventilation, and consideration of neurosurgery consultation and i.v. anaesthetics for burst-suppression pattern on electroencephalography, as recommended in the study 1.

Monitoring and Adjustments

• Frequent monitoring of serum sodium and electrolytes is crucial to adjust the infusion rate and prevent complications such as rebound cerebral edema, renal failure, electrolyte abnormalities, hypovolemia, and hypotension.
• The study emphasizes the importance of performing metabolic profiling every 6 hours and daily CT of the head to adjust medications and prevent complications 1.

From the Research

Dose of Hypertonic Saline

• The dose of hypertonic saline for treating hyponatremic encephalopathy is a critical aspect of management, with studies suggesting different approaches 2, 3, 4.
• A bolus of 100 mL of 3% saline, given over 10 minutes, is recommended for patients with hyponatremic encephalopathy exhibiting neurologic manifestations, with the goal of quickly treating cerebral edema 2.
• However, a study comparing 100 mL and 250 mL NaCl 3% rapid bolus therapy found that the larger dose was more effective in increasing serum sodium levels without increasing the risk of overcorrection 3.
• Another study found that treatment with 150 mL of 3% hypertonic saline was effective in increasing serum sodium levels, but the overcorrection rate was high, especially in severely symptomatic patients 4.
• The total change in serum sodium should not exceed 5 mEq/L in the initial 1-2 hours and 15-20 mEq/L in the first 48 hours of treatment to avoid cerebral demyelination 2, 5.

Administration and Monitoring

• Hypertonic saline should be administered with caution, and patients require frequent monitoring to avoid overcorrection and cerebral demyelination 2, 6, 5.
• The infusion rate and volume of hypertonic saline should be adjusted based on the patient's response and serum sodium levels 2, 4.
• Reducing bolus-volume and reevaluation before repeating bolus infusion might prevent overcorrection, especially in severely symptomatic patients 4.

Clinical Considerations

• The treatment of hyponatremia should be individualized based on the underlying cause, severity, and symptoms of the disease 2, 6, 5.
• Clinicians should be aware of the potential risks and benefits of hypertonic saline therapy and monitor patients closely to avoid complications 2, 3, 4, 5.